Automatic cut-off valve.



J. 0. SMITH. AUTOMATIC OUT-OFF VALVE. APPLIOATION rmzn AUG. 1a, 1908.

Patented Sept. 13, 1910.

A TTORNEY 7n: mum! FETIRS (0,, wunmcrnm n. c.

UNITED STATES ATENT oEEIoE.

JESSE C. SMITH, OF KANSAS CITY, MISSOURI.

AUTOMATIC CUT-OFF VALVE.

To all whom it may concern:

Be it known that I, JEssE C. SMITH, a citizen of the United States,residing at Kansas City, in the county of Jackson and State of Missouri,have invented certain new and useful Improvements in Automatic Cut-offValves, of which the following is a specification.

This invention relates to automatic cutoff valves; and'my object is toprovide a simple and efficient valve of this character which willautomatically cut off the flow of gas from a supply-pipe should thepressure therein be materially reduced or the supply of gas betemporarily cut oil.

With the above object in view the inven tion may be said to reside inthe novel combination and arrangement of parts hereinafter described,illustrated in the accompanying drawing, and particularly pointed out inthe claims, it being understood that changes in form and minor detailsof construction may be resorted to without departing from the spirit orscope of the invention.

Referring now to the accompanying drawing which illustrates theinvention: Figure 1 represents an end elevation of the device partly insection. Fig. 2 is a plan view of the device with a portion of thehousing, employed in carrying out the invention, removed. Fig. 3 is anirregular section of the valve when closed on line III- 111 of Fig. 1.Fig. 4 is a side elevation of a modified form of the device partlybroken away to show the interior thereof.

In carrying out the invention, I employ a valve consisting of a casing1, a plug .2 arranged therein, and a stem 3 to which the plug is fixed.Casing 1 is provided with a port 4 surrounded by a plug-seat 5, which isinclined so that when plug 2 is seated thereon it will be reliably heldin a closed position by the pressure of the fluid acting thereon. Stem 3extends outward through one side of the casing, which is provided with astuffing-box 6 to prevent leakage of fluid around the valve-stem.

7 designates a housing carried by easing 1 and provided with a diaphragm8 which extends across the interior of the housing and forms anexpansion chamber 9 in the upper portion thereof. The lower portion ofhousing 7 is provided with a slotted guide 10 through which the free endof stem 3 extends. Said stem is normally held in a raised position by alatch 11, pivotally se- Specification of Letters Patent.

Application filed August 18, 1908.

Patented Sept. 13, 1910.

Serial No. 449,078.

cured at its upper end to housing 7 by a pin 12, and provided at itslower end with two inwardly-extending arms 13 14, either of which isadapted to engage the stem 3.

The upper portion of latch 11 is provided with an arm 15 extendingsubstantially at right angles thereto and provided with a screw 16 whichis adjustable so that its upper terminal may be arranged in properrelation to the diaphragm. Arm 15 is also provided with a transverse pin17, the ends of which project beyond the sides thereof and engage aspring 18, secured to the lower portion of housing 7, which holds thelatch in such position that its arm 13 will intersect the slottedportion of guide 10 and support stem 3 in its raised position.

19 designates a hot-air coil closed at one end and communicating at itsopposite end with chamber 9.

When the device is used in connection with a gas-stove or furnace, it isconnected to the main su ply-pipe in such manner that the gas will owthrough the valve in the direction of arrow a. The valve may beconnected to said supply-pipe any convenient distance from the furnace,but the coil 19 is arranged adjacent to the furnace-burner so that theair within said coil Will become heated within a short itme after theburner has been li hted. The valve is opened by hand to allow thepassage of gas to the burner by raising its stem 3 until it is engagedby the upper surface of arm 13, which supports the stem until the airwithin the coil 19 becomes heated, expands into chamher 9, and depressesthe diaphragm to the dotted position shown in Fig. 1. When this occursthe diaphragm contacts with screw 16 and depresses the same therewith,causing it to throw latch 11 to the position indicated by dotted lines,Fig. 1, and release arm 13 from stem 3 so that the latter may drop ontoarm 14 which has been drawn across the slotted portion of guide 10 tointercept the downward movement of the stem. The stem remains supportedby arm 14 so long as the gas flows to the furnace-burner and the latterremains lighted, but should the flame be blown out or the flow of gasthereto be temporarily interrupted, the air within coil 19 becomes cooland contracts, thereby allowing the diaphragm 8 to resume its normalposition. When this occurs, spring 18 pressing upward on pin 17 throwsthe latch to the position shown in full lines,

Fig. 1, and thereby withdraws arm 15 from I beneath stem 3, so thelatter may descend and permit plug 2 to become seated. Further flow ofgas to the burner is then prevented until the stem is again raised intoengagement with arm 13.

In the modified form, Fig. 4, the construction is substantially the sameas that in the preferred form, with the exception that arm 13 of latch11 is removed, and a dash-pot 13 is substituted therefor. Said deviceconsists of a valve 1 provided with a plug 2*, secured to a stem 3extending outward from the valve through a stuffing-box 6*. Valve 1 hasa port 4* surrounded by an inclined seat 5 to receive plug 2*. 7designates a housing secured to the valve casing and provided with aslotted guide 10*, through which the valve-stem extends. l1 designates alatch mounted in housing 7 and provided at its lower terminal with anarm 14 adapted to intersect the slotted portion of guide 10* and preventstem 3 from dropping therethrough until the supply of gas is cut off.The free end of stem 3 extends into the dash-pot cylinder 20, and isconnected to a piston-head 21 by a connecting-rod 22.

In practice the device is set in an operative position by raising stem3*, which is prevented from immediately dropping downward by thepiston-head 21, which moves downward very slowly and permits thediaphragm in chamber 9 to actuate latch 11 and draw arm 14L beneath thestem. Then should the flow of gas be interrupted the diaphragm willcontract and allow latch 11 to resume its normal position, therebydrawing arm 14 from beneath the stem which drops rapidly and permitsplug 2 to become seated. The initial downward movement of thepiston-head 21 is exceedingly slow by reason of the fact that air entersthe top of cylinder 20 only through a small opening 23, but after thestem moves down ward and rests upon arm 14?, the pistonhead passesbeneath slots 24 in the cylinder and permits a free circulation of airabove the piston-head, so that the latter will not retard the downwardmovement of the valve-stem after arm ll has been withdrawn from beneaththe same.

Having thus described my invention, what I claim is 1. An automaticcut-off valve, comprising, in combination, a Valve having an oscillatoryarm, a housing carried upon the valve casing, a diaphragm extendingacross the interior of said housing and forming an expansion chamberthere-in, and means adapted to engage said arm for holding said valvewhereby upon automatic release from one position, said meansautomatically and simultaneously interposes itself in position to catchthe valve in a second position, said holding means being adapted to becontacted by said diaphragm to operate said holdmg means.

2. An automatic cut-off valve, comprising, in combination, a valvehaving an oscillatory arm, a housing carried upon the valve casing, adiaphragm extending across the interior of said housing and forming anexpansion chamber therein, and a device adapted to intercept said arm inits oscillations to hold the latter in one of aplurality of positions,said device consisting of arm supporting fingers, and a diaphragmcontacting element.

' 3. An automatic cut-off valve, comprising, in combination, a valvehaving an oscillatory arm, a housing carried upon the valve casing, adiaphragm extending across the interior of said housing and forming anexpansion chamber therein, and means adapted to engage said arm forholding said arm in one of a plurality of positions, said. arm engagingmeans comprising a pivoted yoke having spaced fingers adapted tointercept said arm in succession, and an element in connection with saidyoke for contacting said diaphragm.

In testimony whereof I aflix my signature, in the presence of twowitnesses.

JESSE C. SMITH.

WVitnesses F. G. FISCHER, M. Cox.

